Tensioning mechanism for winding machines



Dec. 8, 1953 M. A. THOM 2,661,914

TENSIONING MECHANISM FOR WINDING MACHINES Filed June 5, 1948 2Sheets-Sheet l Dec. 8, 1953 M. A. THOM 2,661,914

TENSIONING MECHANISM FOR WINDING MACHINES Filed June 5, 1948 v 2Sheets-Sheet 2 INVEN TIOR. fizviwflyam Patented Dec. 8, 1953' "YT-,1

renew TENSEONING- MECHANESM FOR WINDING MACHENES Melvin A. Thom,Brighton, N. Y.

Application June 5, 1948, Serial No. 31,237

15 Slaims.

This invention relates to a tensioning mechanism for winding machines,with particular reference to handling fine wire such as employed inwinding electrical resistors, and has for its purpose to aiiord astructure that will maintain a substantially constant and uniformtension on winding material such as wire as it is being wound on to aform, and will maintain the wire against movement when the windingoperation is interrupted.

A more particular purpose of the invention is to afford a constructionin which the winding material or wire passes around a tensioning rolland is gripped by a resilient frictional or ruboer-like periphery on theroll, movement of the tensioning roll being retarded to a varying degreedepending upon the tension exerted on the wire by the winding mechanism,thus lessening the retarding of the tensioning roll as the winding pullon the wire increases and increasing the retarding of the tensioningroll as the winding pull on the wire decreases, in order to maintain avarying retarding action on the tensioning roll in accordance with thevariations in the pull exerted on the wire at the winding point, and

serving to hold the wire against movement by engagement of thetensioning roll therewith when the winding operation is temporarilydissive changes in tension which are obviated To this invention. a V

A further purpose of the invention is to afford mechanism that will holda wire or thread stationary during interruption of the winding machineoperation as for instance where the winding mechanism is reversed toremove a quantity of wire, thus enabling more successful and efficientwinding of electrical resistors requiring close tolerances of from plusor minus one per cent to plus or minus one-tenth of one per cent, owingto maintaining constant, even tension and consequently greateruniformity in the winding of wire on a resistor form.

An additional object of the invention is to enable a wide range ofadjustment of the tension exerted on the wire while being wound, and byreason of such wide range and the uniformity of any selected tension, tofacilitate manufacturing electrical wire-wound resistors so as to obtainmore wire on a given winding form for a given wire size and resistancerange, thus increasing the efliciency of the resistor as well as therange of resistors than can be wound when governed with such atensioning mechanism.

Still a further purpose of the invention is to reduce the tensionexerted on the supply reel from which the wire is unwound, controllingthe wire by atensioning r011 located between the supply reel and theunwinding point and acting to hold the wire frictionally so as toprevent excessive tension on the supply reel, and by the use of rubberor other rubber-like or resilient frictional peripheral surfaces onpositioning and tensioning rolls around which the wire travels, toafford mechanism for handling enamelled wire without damage to theenamel during the winding operation. 7 I

Another object of the invention is to afford a practical mechanism thatcan readily be arranged to accommodate any size wire, thread, or otherwinding material, is adaptable to any winding speed, and will afford therequired friction between the wire and tensioning roll to preventslippageo'f the wire thereover.

Any additional purpose of the invention is to afford a mechanism ofsimple, and practical construction which can be easily and quicklyadjusted and controlled for any required size of wire or thread, for anywinding speed, and for any required retarding action on the tensioningroll.

To these and other ends, the invention consists in the construction andarrangement of parts that will appear clearly from the followingdescription when read in conjunction with the accompanying drawings, thenovel features being pointed outin the claims following the speciiication.

In the drawings:

Fig. 1 is a view in side elevation showing a mechanism constructed inaccordance with a preferred embodiment of the invention and i1-lustrating the position of the control device and brake when there istension on the winding material at the winding point and the retardingac- 3 oration, and the retarding action on the tensioning roll isincreased;

Fig. 3 is a plan view, and

Fig. 4 is an enlarged detail vertical sectional view on line dl of Fig.1 looking in the direction indicated.

It is to be understood that the invention may be carriedout in a varietyof ways,,being adapt: able to the winding of wire, thread, or any othermaterial that is to be unwound from a supply reel and wound on to areceiving form such as.

a porcelain body in the case of an electrical wirewound resistor, andthe structure. shown herein. is intended only as illustrative of onepractical embodiment of the invention.

Referring more particularly to the drawings in which like referencenumerals refer to the same parts throughout the several views, Idesignates a suitable base. or support to which is attached the sidebrackets 2 within which are removably arranged suitable ball bearingassemblies adapted to receive the shaft 3 supporting the supply reel 4from which the wire 5- or other winding material is unwound, while 3designates adjusting nuts for securing the supplyreel on the shaft 3.Any suitable conventional means may be employed for slightly retardingmovement of the shaft 3 so as to prevent free spinning motion of thesupply reel while at the same time permitting proper movement thereofas, the wire is drawn therefrom for winding on to a porcelain resistorbody or other form.

The wire 5 after leaving the supply reel 4 travels around a rotatableidler positioning roll i, see Figs; 1 and 3, that" preferably isprovidedM ing roll I being mounted on a shaft" 8' that is suitably journalled inthe brackets 9' mounted at the sides of the base I.

Referring to Figs. 1 and, 2, the wire 5 travels around the positioningroll I clockwise and as it leaves the positioning roll, ittravels-upwardly and rearwardly around a tensioning roll II arrangedparallel to the positioning roll and with its longitudinal axis somewhatbelow that of the positioning roll and in a vertical plane oflsetrearwardly from that of the positioning roll. The tensi'onirig ro l isprovided with a resilient frictional. periphery of gum rubber orrubber-like material that prevents the wire from slipping thereover, andthe wire travels around the ten sioning roll II anti-clockwise, thenceupwardly and forwardly to a control device that will presently bedescribed.

The tensioning roll I I is supported by trunnions I2 mounted in. thebrackets 9, see Fig. 4,

and in order to impose a retarding or braking action on the tensioningroll II, the trunnions I2 have fixed. thereon at their ends the brakingdisks I3 which rotate with. the tensioning' roll I! and are permitted totravel. more freely as the tension on the wire atthe Winding. pointincreasesand less freely as the tension on the wire at the winding pointdecreases and thus to retard movement of the windingmaterial'.

To effect such retarding of the tensioning roll,

there are provided brake shoes I4 having felt or other frictionalsurfaces I5 engaging the-braking disks I3. The brake shoes I4 are heldagainst the braking disks by spring arms I6 on which they are mountedand which are fixedly and adjustably secured on the ends; of a spindleI1 which is journalled in the brackets 9 and has an oscillating movementin accordance with the varying tension exerted on the wire at the winding .point. Such oscillating movement of the spindle I1 acts to move thespring arms I8 and the brake shoes radially of the braking disks I3, andwhen the brake shoes are at the outermost points of the braking disksi3, movement ofthe tensioning roll H is; retarded to a maximum degree,whereas when the brake shoes are moved inwardly toward the center of thebraking disks I3, retarding of the tensioning roll 8! is: reduced: topermit the correspondingly freer movement of the wire or windingmaterial as the... tension at. the winding point is increased.

The brake shoes are moved radially of the braking; disks; by mechanismthat is controlled 'by the, tension on the strand of wire or threadatthe winding point and to this end the brake shoes are operativelyconnected to a control device that is engaged by the strand of windingmaterial as the latter travels therethrough. To accomplish this, thespindle I! has mounted therein two supporting arms or rods I8 which areadjustable transversely of the spindle I? and carry at their forwardends a mounting I9 on which is pivotally supported a bracket 2| by meansof a post 22 permitting the bracket 2! to swivel about the mounting I9as the position of the strand changes during unwinding from the supplyreel 4, and 23 designates. a control pulley mounted in the bracket 2I toreceive the strand or wire and to maintain the same in corn trollingrelationship to the supporting arms It, while 2t" designates adjacentlyarranged guide pins between which the strand passes before reaching thecontrol pulley 23, the guide pins 24 being provided with horizontalterminal portions 25 which are suitably fixed to the bracket 2|. Aftertravelling over the control pulley 25, the wire, thread, or other strandpasses downwardly under a guide pulley 2S rotatably sup ported in abracket 21 that is fixed to the base I, and thence the strand passestothe winding pointindicated at 28 where the wire is wound on a porcelainresistor body or other form in tended to receive the strand of windingmaterial by means of any conventional winding apparatus.

The brake shoes are maintained in a normal operative relationship to thebraking disks I3 by adjustable spring-controlled means connected tospindle I7, and to effect this, there are provided the rods 29, each ofwhich is secured at one end to the spindle I! and engaged at itsopposite end by a coil spring 3 I. The lower ends of the springs 3I areconnected to posts 32 which are fixed to an adjustable rock shaft 33that carries a worm gear 34 fixed thereon, while 35 designates anadjusting worm mounted on a suitable bearing and geared to the worm gear34 so that by turning the worm 35, the tension on the Springs 3I can bevaried to effect a greater or less pullon the rods 29 and thus adjustthe position of the spindle IT and the brake shoes for their normaloperative relationship when maximum tension is exerted on the strand atthe winding point, and also tovary the tension of the springs 3 I- asthey actuate the brake shoes outwardly in a radial direction withrespect to the braking disks when tension on the strand at the Windingpoint is decreased.

The operation of the mechanism briefly is as follows: The strand ofwire, thread, or other winding material as it is wound on to a form isacorn-14 drawn from th supply reel el over and around the positioningroll 'l in a clockwise direction, thence rearwardly, upwardly, andaround the tensioning roll H in an anti-clockwise direction, thenceupwardly between the guide fingers 2d and over the control pulley 23 ina clockwise direction, thence downwardly and under the guide pulley inan anti-clockwise direction, and thence upwardly to the winding point28. When the winding material is being wound on to a form with maximumtension, the pull on the strand holds the control pulley 23, mountingI9, and supporting arms it in a lowered position, as illustrated in Fig.1, and in such position the brake shoes approach the center of thebraking disks and impose a minimum retarding action on the disks,permitting a more free movement of the tensioning roll H. The tensioningroll ll having a gum rubber or other resilient, frictionalsurfaceengaging the strand of wire or thread efiectively prevents any slippageof the latter over the surface of the tensioning roll so that the strandcan travel no faster than the tensioning roll permits, and as the pullor tension exerted on the strand at the winding point decreases,correspondingly less pull is exerted on the control pulley 23, mountingill, and supportingarins l8, permitting the latter to lift from theposition shown in Fig. 1 to the position shown in Fig. 2 dueto theaction of the springs 3| which determine the position of the spindle l1and hralre shoes when tension is released on the strand. As this occurs,the brake shoes move outwardly toward the periphery of the braking disks:3, as illustrated in Fig. 2, and exert a correspondingly greaterbraking action on the braking disks and thus retard movement of the ten-7 cloning roll ii so that the strand is preventedfrom travelling beyondthe tensioning roll I i any faster than the winding mechanism or tensionat the winding point requires. If for-any, reason the winding mechanismis entirely stopped or interrupted for a time, the tensioning roll lllosing held against movement by the brake shoes acting on the brakingdisks in turn holds the strand or wire against movement around thetensioning roll and prevents excessive slack in the strand between thetensioning roll and the Winding point. The unwinding movement of thesupply reel is retarded sufficiently to prevent removal of the strandtherefrom at a faster speed than it travels around the tensioning rolland the action of the tensioning roll in combination with the ositioningroll "5, and their relation to each other, serves to hold the strandagainst movement or slack when the winding operation is interrupted,also to maintain a normally constant and uniform tension on the strandat all times during the winding operation. As the strand is unwound fromthe supply reel 4 at different points endwise of th latter, suchvariable position of the strand is compensated for by the control pulleyand racket 2i swiveling in a 7 horizontal plane about the mounting it sothat cover such modifications and departures as may and the scope of thefollowing claims.

I claim: r l l. Tensioning mechanism comprising a supply reelforwindingmaterial, a rotatable tensioning r011 having a frictionalperipheral surface around which winding material passes as it is unwoundfrom said supply reel, retarding means comprising a braking disk securedto the tensioning roll to rotate therewith and having a braking face ina plane at right angles to the axis 'of said tensioning roll, abrakeshoe engaging the braking face of said disk and movable radially of saidaxis to vary the retarding action on the tensioning roll a controldevice connected to the brake shoe acting to eflect said radialmovement, said control device including an element engaged by thewindingmaterial andmovable thereby in one direction to move the brake shoeradially toward axis to decrease the retarding action on the tensioningroll, and spring means actuating the brake shoe in the oppositedirection to increase the retarding action on the tensioning roll.

Tensioning mechanism comprising a rotatable tensioning roll having aresilient, frictional peripheral surface around which winding materialpasses, retarding means comprising a braking disk connected to thetensioning roll, a brake shoe engaging said disk and movable, radiallythereof to vary the retarding action on the tensioning roll, a controldevice connected to the brake shoe acting to efiect said radialmovement, said control device including an element engaged by thewinding material and movable thereby in one direction to decrease thretarding action on, the tensioning roll, and spring means actuating thebrake shoe in the opposite direction to increase the retarding action onthe tensioning roll.

3. Tensionlng mechanism comprising a rotatable positioning roll, arotatable tensioning roll arranged-parallel to'the positioning roll andhaving a friction periphery around'which winding material passes afterleaving the positioning roll, retarding means comprising a braking diskconnected to the tensioning roll, a brake shoe engaging said disk andmovable radially thereof to vary the retarding action on the tensioningroll, a control device connected to the brake shoe acting to efiect saidradial movement, said control device including an element engaged by thwinding material and movable thereby in one direction to decrease theretarding action on the tensioning roll, and spring means connected toand actuating the brake shoe the opposite direction to increase'theretarding action on the tensioning roll.

4, Tensioning mechanism comprising a rotatable positioning roll, arotatable tensioning roll arranged parallel to the positioning roll andhaving a resilient friction periphery with its longitudinal axis locatedbelow that or" the posi- I tioning roll and in a vertical plane offsettothat of. the positioning roll whereby winding material passing aroundthe positioning roll travels thence upwardly and rearwardly before goingaround the tensioning roll, retarding means comprising a braking diskconnected to the tensioningrcll, a brake shoe engaging said disk andmovable radially thereof to vary the retarding action on the tensioningroll, a control device connected to the brake shoe and acting to effectsaid radial movement, said control device including an element engagedby the winding material and movable thereby downwardly to decrease theretard- '5"- ing action o the tensionins ro l, and spring meansactuating the, brake shoe oppositelyto increase the retarding action onthe tensioning roll.

5. Ten ioning mechanism comprising a rotat able, positioning roll,having a resilient friction periphery around which Winding materialtravels, a rotatable tensioning roll arranged parallel, and injuxtarelation to the positioning roll, thev tensioning roll having aresilient friction periphery with its longitudinal axis located belowthat of the positioning roll and in a vertical plane offset to that ofthe positioning roll whereby the winding material passing around thepositioning roll travels thence upwardly and rearwardly be-. fore goingaround the tensioning roll, retarding means operatively associated withthe tensioning roll and movable in relation thereto to vary theretarding action, a control device operatively connected to theretarding means and movable as the tension on the winding materialvaries, the control device being located somewhat above said tensioningroll and including a controlpulley over which the winding materialpasses after leaving the tensioning roll, and a guide pulley locatedbelow and in advance of the control pulley and under which the windingmaterial passes after leaving the control pulley.

6. Tensioning mechanism comprising a rotatable positioning roll and arotatable tensioning roll arranged parallel thereto, the positioning andtensioning rolls having rubber-like friction peripheries around whichwinding material passes successively, retarding means comprising abraking disk connected to the tensioning roll, a, brake shoe engagingsaid disk and movable radially thereof to vary the retarding action onthe tensioning roll, a control device connected to the brake shoe actingto effect said radial movement, said control device including an elementengaged by the winding material and movable thereby in one direction todecrease the retarding action on the tensioning roll, and spring meansactuating the brake shoe in the opposite direction to increase theretarding action on' the tensioning roll.

7. Ifensioning mechanism comprising a rotatable positioning roll and arotatable tensioning roll arranged parallel to the positioning roll withits longitudinal axis located below that of the positioning roll and ina vertical plane, ofiset to that of the positioning roll whereby windingmaterial passing around the positioning roll travels thence upwardly andrearwardly before going around the tensioning roll, said positioning andtensioning rolls having rubber-like friction peripheries around whichthe winding material travels successively, retarding means comprising abraking disk connected to the tension,- ing roll, a brake shoe engagingsaid disk and moving radially thereof to vary the retarding action onthe tensioning roll, a control device connected to the brake shoe andacting, to effect said radial movement, said control device includin anlement encas d by h W nd ng material and movable thereby in onedirection to decrease the retarding action on the tensioning roll, andspring means actuating the brake shoe in. the opposite direction toincrease the retarding action on the tensioning roll.

8. Tensioning mechanism comprising a rotatable positioning roll and arotatable tensioning roll arranged parallel and in juxtarelation to thepositioning roll with its longitudinal, axis below that of thepositioning roll and in a ver-.

tical. p ne offset to, that Q 1 he posit on ng. oll wher by he. windi gm t r al. passing a ound the positionin roll traye s enc upward andrearward y before goin around th t nsi n e roll, th p sition and t ns nne r l havin ru ber-like iri ti nr periphe s aro w i h the windinmateria r v ls succ y r a din mea s. c mpris ng a braking i k c ted tothe te sicn ng o l, a rake. ho nga in said disk. and moving radia y h ref. to ary t e retard g act n. o the cnsion ne r ll, a coniOl dev ce.QQIHlQQ d Q he brake 1 n tg t e ect. said radial mov m nt, s d ntr devicincluding an elem nt ne e dby the w n ng; mater al d mov bl t e y n, nedir tion to decrease the retardin ac on e t nsionine roll, and hi m tu tthe rals s oe in the opposite, directionto i r a the. retard n actio on.t ing roll.

9., Iensioning mechanism comprising a rotata l t nsi nine roll h ving afr o p r ph ry round wh chwin ins m te ia rav r in means comprising abraking disk connected to the. tensioning roll, a brake shoe engagingsaid braking dish and movable radially thereof, an oscillatory spindleon which said brake shoe is mounted, a control device includingsupporting arms extending through said oscillatory spindle, rods carriedby said spindle, a spring connected to each of, said rods at one end andto an adjustable stationary post at its opposite end, a mounting carriedby the opposite ends of said supporting arms, a bracket secured to saidmounting, and rotatable means carried by the bracket and engaged by thewinding material after it leaves the tenslonine roll.

10. Tensioning mechanism comprising, a rotatable tensioning roll havinga friction periphery around which winding material travels, retardingmeans comprising a braking disk connected to the. tensioning roll, abrake shoe engaging said braking disk and movable radially thereof, anoscillatory spindle on which said brake shoe is mounted, a controldevice includ ing supporting arms extending through said oscillatoryspindle, rods carried by said spindle, a spring connected to each ofsaid rods at one end, and to a stationary post at, its opposite end, amounting carried by the opposite ends of said supporting arms, a bracketrotatably supported on said mounting for swiveling movement in agenerally horizontal plane, a control pulley carried by said bracket forguiding the winding material thereover, guiding fingers attached to thebracket and located in advance of said control pulley, and a guidepulley mounted in a stationary bracket located beneath said controlpulley.

ll. Tensioning mechanism comprising a rotatable tensioning roll having afriction periphery around which winding material travels, retardingmeans comprising a braking disk connected to the tensioning roll, abrake shoe engaging said braking disk and movable radially thereof, anoscillatory spindle on which said brake shoe is mounted, a controldevice including supporting arms adjustable on said osciilatoryspindle,rods carried by said spindle, a spring connected to each of said rods atone end and to a post at its opposite end, a rock shaft on which saidposts are mounted, a worm gear on said shaft, an adjusting wormconnected to said worm gear, a mounting carried by the opposite ends, ofsaid. supporting arms, a bracket r0 tatably supported on said mountingfor swiveling movement in a generally horizontal plane, a control pulleycarried by said bracket for guiding the winding material thereover,guiding fingers attached to the bracket and located in advance of saidcontrol pulley, and a guide pulley mounted in a stationary bracketlocated beneath said control pulley.

12. Tensioning mechanism comprising a rotatable positioning roll and arotatable tensioning roll arranged parallel and in juxtarelation to thepositioning roll with its longitudinal axis below that of thepositioning roll and in a ver' tical plane offset to that of thepositioning roll whereby the winding material passing around thepositioning roll travels thence upwardly and rearwardly before goingaround the tensioning roll, the positioning and tensioning rolls hav ingrubber-like friction peripheries around which the Winding materialtravels successively, retarding means comprising a braking diskconnected to the tensioning roll, a brake shoe engaging said disk andmoving radially thereof to vary the retarding action on the tensioningroll, an oscillatory spindle on which said brake shoe is mounted, acontrol device including supporting arms adjustable on said oscillatoryspindle, rods carried by said spindle, a spring connected to each ofsaid rods at one end and to an adjustable post at the other. end, amounting carried by the opposite ends of said supporting arms, a bracketrotatably supported on said mounting for swiveling movement in agenerally horizontal plane, a control pulley carried by said bracket forguiding the winding material thereover, guiding fingers attached to thebracket and located in advance of said control pulley, and a guidepulley mounted in a stationary bracket located beneath said controlpulley.

13. Tensioning mechanism comprising a rotatable tensioning roll aroundthe periphery of which winding material travels, retarding meanscomprising a braking disk connected to the tensioning roll and having abraking face in a plane at right angles to the axis of said tensioningroll, a brake shoe engaging the braking face of said disc and movableacross said face radially of the axis of said tensioning roll, a spindleoscillatable about an axis parallel to the axis of said tensioning roll,an arm rigidly connecting the brake shoe to the spindle so that the position of the brake shoe across the face of the disc is varied on movementof the spindle, means for constantly urging said spindle in a directionto move the brake shoe radially away from the axis of the braking disc,and means for moving the spindle in the opposite direction about itsaxis comprising a supporting arm secured to the spindle, a bracketmounted for swiveling movement on the free end of said supporting arm,and a roll journaled in said bracket over which the winding materialpasses after it leaves the tensioning roll, said second named roll beingmounted in said bracket for rotation about an axis at right angles tothe axis 01' swivel of said bracket.

tatable tensioning roll having a frictional peripheral surface aroundwhich winding material travels, retarding means comprising a brakingdisk connected to said tensioning roll to rotate therewith and having abraking face in a plane at right angles to the axis of said tensioningroll, a brake shoe engaging said braking face and movable radiallythereof, an oscillatory spindle on which said brake shoe is carried,said spindle being mounted for rocking movement about an axis parallelto the axis of the tensioning roll, a control device including two rodssecured to said spindle and projecting from opposite sides thereof, aspring connected to the free end of one rod and adapted to constantlyurge said brake shoe radially away from the axis of said tensioningroll, a mounting carried at the free end of the other rod, a bracketswivelly mounted in said mounting, and a, pulley rotatably mounted insaid bracket for rotation about an axis at right angles to the axis ofswivel of-said bracket and engaged by the winding material after itleaves the tensioning roll.

15. Tensioning mechanism comprising a rotatable tensioning roll having africtional peripheral surface around which winding material travels,retarding means comprising a braking disk connected to said tensioningroll to rotate therewith and having a braking face in a plane at rightangles to the axis of said tensioning roll, an oscillatory spindlemounted to 'rock about an axis parallel to the axis of said tensioningroll, a flexible arm secured at one end to said spindle, a brake shoecarried at the other end of said arm and engaging the braking face ofsaid braking disk, said arm being flexed to press said brake shoeresiliently against said braking face, a pair of rods secured to saidspindle and projecting from opposite sides thereof, a spring connectedto the free end of one rod and adapted to constantly urge said spindlein one direction about its axis to move said brake shoe radially acrosssaid braking face away from the axis of said tensioning roll, a bracketswivelly mounted on the free end of the other rod, and

g a pulley rotatably mounted in said bracket for rotation about an axisat right angles to the axis of swivel of said bracket and engaged by thewinding material after it leaves said tensioning roll.

MELVIN A. THOM.

References Cited in the file of this patent UNITED STATES PATENTS

